Will Fracking The Marcellus Shale Frack Washington DC?

A large shale deposit called the Marcellus Shale covers all of West Virginia, the western 4/5 of Pennsylvania, and most of the southern half of New York. It contains natural gas, embedded in the rock. Energy companies are filling deep holes with explosives and chemicals and "fracking" the shale - breaking it up - so that the natural gas can accumulate and be captured and sold.

New York City is worried about toxic chemicals from fracking appearing in its water supply. Perhaps Washingtonians should be worried, too.

Once long ago as I was driving out highway 80 from New York to Chicago, I stopped for a break at, I think, the town of Clearfield in mid Pennsylvania. I was told as I sipped my coffee that there is a massive spring in the town whose water comes from the Susquehannock forest to the north and is sent through a long aqueduct to the Baltimore-Washington Area, into the "Washington Aqueduct" system. Does this mean that fracking in PA could poison the water in DC?

Can one ask the powers that be how much of Washington's drinking water comes from Pennsylvania? Does it come from areas where the energy companies plan to frack?